With the assassinations last week the regime’s intelligence chief and the defense and interior ministers, the appeal of becoming Target Number One is dwindling. “There’s really no one in the regime that the opposition would accept at this point and they’d likely continue to fight,” says Joseph Holliday, a Syria analyst at the Institute for the Study of War. “Even Tlas, who is Sunni and could bridge the gap, two of his own cousins high up in the opposition have said that they wouldn’t accept his leadership.”

Much of the problem is Syria’s sectarian divides. Half of the country is Sunni and Assad’s Alawite minority, which makes up 12% of the population, has repressed them for decades. But if you install a Sunni leader, the risk is marginalization of not just the Alawites and other Shia, but also the Kurdish, Druze and Christianpopulations, which together make up 30% of the country. “There is a real risk of a failed state here. We don’t do tribal societies well. We don’t understand them and we don’t really know how to change them,” says Jane Harman, head of the Woodrow Wilson Center in Washington, adding that intense external interests also complicate the situation.

The two most recent topplings of authoritarian governments in tribal societies in that neighborhood do not bode well for Syria: Lebanon and Iraq. Lebanon’s civil war lasted 15 years and claimed hundreds of thousands of lives. The U.S. removed Saddam Hussein in Iraq, but nearly a decade after the invasion Iraqstill suffers from high levels of sectarian fighting; on Tuesday alone morethan 100 people were killed in violence believed to be spilling over from Syria. “One of the reasons the Administration and others are chary about intervening in Syria is that it’s similar to Iraq where there’s a minority – in Iraq’s case Sunni – that had been repressing a majority. When the Shia were freed they began to take revenge. Sunnis were driven out of whole neighborhoods in Baghdad,” says James Dobbins, a civil society exert at the Rand Corporation. “You have the reverse in Syria – a Shia minority and a Sunni majority – but there’s no reason why we wouldn’t see the same trend of retribution in Syria. Not that that’s a reason not to get involved, because if we don’t it’ll probably be worse.”

Except for humanitarian aid and communications equipment – and recently intelligence (how else did the opposition manage to bomb what was essentially a sitcom meeting in Damascus last week?) — the U.S. has taken a hands off approach,essentially sub-contracting the arming of the rebels to Saudi Arabia, Qatar, the United Arab Emirates and Turkey. “The problem is they don’t share our long-term interests in a post-Assad Syria; the Saudis and Qataris, for example, back groups – Jihadists and extremists – that we don’t like,” says Andrew Tabler, an Arab expert at the Washington Institute for Near East Policy and author of In the Lion’s Deb: An Eyewitness Account of Washington’s Battle with Syria. “So by not arming the rebels and not doing more with them you take yourself out as a major player among groups with guns who are likely to play a major role in a post-Assad Syria and that’s a major problem.”

For too long, Washington was hoping that the conflict in Syria would simmer down, Tabler says, and they also bet too much on building relationships with exiled political parties and only in recent months have begun to establish ties with the groups in the ground. The U.S. had been hoping to convince Russia to use their clout with Assad to get him to step aside and allow a Yemeni-style transition where the head of state leaves but the regime remains. Russian and European diplomats in Washington acknowledged that behind the scenes for months they were looking for a suitable replacement for Assad, but such a person never presented himself. Ultimately, Russia would not agree to forcibly removing Assad, vetoing last week yet another United Nations Security Council resolution that would’ve allowed use of force in Syria. That vote prompted U.S. Ambassador to the UN Susan Rice to declare that after 15 months the UN peace process had “utterly failed.”

The Administration, not surprisingly, vehemently rejects these criticisms. “Assad said he’d gas any foreign troops that enter the country. I can’t possibly understand the logic of then arguing for foreign troops on the ground in Syria,” says a senior administration official. “We are leading the effort to squeeze Assad’s finances and to sanction him, to push for a political transition… Providing arms isn’t the only way to get leverage in the future regime. What these guys need is help for the day after. Not just funding-wise, but in terms of UN peacekeepers, diplomatic assistance. They’ll also need help with their chemical weapons. We’re actually providing them with a lot.

“That’s why we need to do this planning now,” the senior administration official says of the Friends of Syria process, which for more than a year has sought to politically unify the opposition groups through a series of meetings held all over the world. “There needs to be work done on what happens the next day after Assad’s gone. What hopefully won’t happen is the dissolution of the state. We need theseinstitutions to have a dialogue with the opposition to help build the next Syrian government.”

Unfortunately, with Syria seemingly coming apart at the seams, a dissolution of the state is increasingly likely. “I don’t think Syria’s destined to have one leader in charge of the whole country at least in the short term,” Holliday says. The most likely scenario now is Assad retreats to the Allawite stronghold of Latakia. Already, he’s having troubling holding Damascus and had to move troops from the Golan Heights to fight off last week’s surprisingly strong offensive by the Free Syrian Army. That would leave Damascus and much of the country in opposition hands. The rest of the country would splinter along ethnic lines, with Kurds retreating to the Kurdish Iraqi border, while Christians and Druze scatter. If that happens, cobbling together a political transition will be hard, even given the advances Friends of Syria has made since January. Earlier this month in Cairo for the first time they unanimously adopted a transition plan. But there is a huge disconnect between the political parties the U.S. has been sheparding and the fighters on the ground. What is likely is that — as Trotsky wrote of Russia after the February 1917 revolution — power in Syria after Assad goes (and indeed even before) will be in the street; the question is, who will pick it up. “If we’re going to see any future leaders of Syria,” Holliday says, “they’re going to come from the ground up where the opposition seizes control.”

New York Times columnist Thomas Friedman notes in his brilliant column on Wednesday that the U.S. played midwife for Iraq. And he worries that without a strongU.S. presence in Syria, things could go very, very wring. “Without an external midwife or a Syrian Mandela, the fires of conflict could burn for a long time,” he writes. Friedmna notes, the U.S. is highly unlikely to play midwife again. And again we hit the same problem of a successor to Assad: there is no Syrian Mandela.

If Syria is allowed to fracture, each ethnic group hunkering down, says Ammar Abdulhamid, an exiled Syria opposition leader in Washington, “it won’t be easy to put humpty dumpty back together again. It would take decades of instability and violence to sort itself out. And that is what we’re most worried about.” Such a civil war or failed state would also have enormous and terrible implications for the whole region. “Syria is Iran’s back door for Lebanon and Israel. It’s one of the hottest of the hotspots in a way that was not the case for Libya,” says Harman. “We have many more strategic interests in Syria than we did in Libya. Syria is a Shia state surrounded by the Sunni crescent, which makes it a proxy for the rest of the Middle East, a Sunni/Shia battleground. There are also huge strategic interests for neighboring Turkey and Israel, not to mention Russia with its port there.” All of which is to say, bringing down Assad without a replacement could be akin to the assassination of Archduke Ferdinand in this climate, on the other hand leaving him in at this point is certainly worse.